In 1987, the California legislature adopted the Air Toxics “Hot Spots” Information and Assessment Act (or AB 2588). AB 2588, and similar legislations, require industrial manufacturers that generate toxic air emissions to notify the public in the immediate area that there may be a risk of exposure to known carcinogenic substances. In addition, AB 2588 requires facilities to submit an air toxics inventory report (“ATIR”). A facility's priority score is calculated from information in the ATIR. A facility with a priority score greater than ten (10) must provide a health risk assessment (“HRA”), following guidelines established by the State of California Office of Environmental Health Hazard Assessment, and supplemented by Air Quality Management District guidelines. If the risk reported in the HRA exceeds specific thresholds, then the facility is required to provide public notice to the affected community.
Quemetco Inc., a secondary lead recycling facility in City of Industry Calif., operates under California's Proposition 65 legislation along with AB 2588. California Proposition 65 requires community notification if a facility emits substances known or identified by the state to cause cancer. The public awareness or notification requirements of the program specify quarterly reporting, direct mail campaigns and media announcements (via newspaper) to those individuals living in the area who may be affected by the emissions. Legislation under AB 2588 also requires identified facilities to conduct HRAs which determine cancer risk and cancer burden as well as an index to acute and chronic health risks as defined in the HRA rules. The values for determining the HRA arc specified in the modeling protocols and values included in the regulations.
In 1992, the California legislature added a risk reduction component, the Facility Air Toxic Contaminant Risk Audit and Reduction Plan (or SB 1731), which required the District to specify a significant risk level, above which risk reduction would be required. In Rule 1402, the South Coast Air Quality Management District Governing Board set the significant risk level at a cancer risk of 100 in a million, and a total chronic or acute hazard index of 5.0. The Board also established action risk levels at a cancer burden of 0.5, a cancer risk of 25 in a million, and a hazard index of 3.0. To better explain what these numbers mean the following definitions from the regulations is provided:                Maximum Individual Cancer Risk (“MICR”): the estimated probability of a potentially maximally exposed individual contracting cancer as a result of exposure to toxic air contaminants over a period of 70 years for residential receptor locations. The MICR for worker receptor locations must also be calculated.        Cancer Burden: the estimated increase in the occurrence of cancer cases in a population subject to an MICR of greater than or equal to one in one million (1×10-6) resulting from exposure to toxic air contaminants.        Acute Hazard Index: the ratio of the estimated maximum one-hour concentration of a toxic air contaminant at a receptor location to its acute reference exposure level.        Chronic Hazard Index: the ratio of the long-term level of exposure to a toxic air contaminant for a potentially maximally exposed individual to the chronic reference exposure level for the toxic air contaminant.Public notification and a public meeting are required for facilities with cancer risks greater than or equal to ten in a million or non-cancer acute or chronic hazard index greater than one. Rule 1402 requires annual public notice until the facility gets below the action risk levels.        
Secondary Lead Smelters produce Pb (lead) and lead alloys from lead-bearing scrap materials. The main source of feed material being spent batteries. The process is generally characterized by three operations: scrap pretreatment, smelting, and refining. Scrap pretreatment operations include the separation of metal and non-metal components from lead-bearing scrap. Operations include battery breaking, plastic separation and removal, and lead crushing. Smelting produces lead by the oxidation of lead sulphates, followed by carbothermic reduction of oxides to elemental lead.
Two lead bearing streams are produced by the furnace. The first is a metallic lead sent directly to the refinery for the production on Sb (Non-Antimonial alloy). The second is a matte which is charged to an electric arc furnace used to recover lead content as high Non-Antimonial content alloy. One result of these processes is the emission of several contaminants to the ambient air. Particulate metals such as lead, Arsenic, Nickel, and Cadmium are emitted from the scrap treatment, smelting, and refining operations as are organics such as benzene, toluene, and xylene. Emissions of nitrogen oxides, sulfur dioxide, and carbon monoxide occur as a result of combustion, smelting, and refining processes. Historically, emissions from secondary lead smelters have been controlled through the use of wet scrubbers for sulfur dioxide reduction, thermal oxidizers to reduce carbon monoxide, and baghouses to reduce emissions of particulate metals.
In view of the foregoing, there is a need in the art for a method to reduce emissions which minimizes employee exposures, and addresses local air toxin regulations and anticipated pollutant reductions in national ambient air quality standards.